Ask the Science Team: Carbohydrates Explained by Dr. Lucas Grant
For this month’s Ask the Science Team post, we had the pleasure of sitting down with Dr. Lucas Grant, the principal scientist at Unicity, right here in Morecambe, to discuss all things carbohydrates—the benefits and downsides, why prioritizing complex carbs over simple carbs is important, and much more. Dive into the Q&A below to uncover the mysteries of carbohydrates and how they impact your overall health and wellness.
What is a carbohydrate?
A carbohydrate is a molecule made up of carbon, hydrogen, and oxygen. In our bodies, carbohydrates are broken down and go through cellular processes to create energy. They are a crucial part of our diet, as they fuel our daily functions. Even our brain relies on carbs to operate optimally.
However, in today’s world, where processed foods are abundant, many of us consume too many processed carbs, which are not beneficial. Broadly, there are two main types of carbohydrates: simple and complex. We should prioritize complex carbs.
What is the difference between simple and complex carbohydrates?
Simple carbs consist of monosaccharides (single sugars) and disaccharides (double sugars). Examples of monosaccharides include glucose, fructose, and galactose. Examples of disaccharides include sucrose (table sugar), lactose (milk sugar), and maltose. Sucrose is a combination of glucose and fructose. Simple carbs are digested and absorbed quickly by the body, which can lead to weight gain if consumed in abundance without adequate exercise.
Complex carbs, on the other hand, are made up of oligosaccharides and polysaccharides—longer chains of sugar molecules. Examples include fiber and starch. Typically, complex carbs cause a slower rise in blood glucose than simple carbohydrates because the chemical bonds between these sugar molecules need to be broken before they can be absorbed into the bloodstream. Some types of fiber can form a gel-like structure in the gut, which helps keep you fuller for longer periods, aiding weight management and supporting normal, healthy blood sugar levels.
Humans can’t digest most fibers due to the lack of necessary enzymes, so the beneficial bacteria in our gut microbiome do this for us, extracting nutrients and converting fiber into other essential energy sources, thus supporting better weight management.
We do have the enzymes to break down starch, which consists of chains of glucose. Foods high in starch typically cause a greater rise in blood glucose than those high in fiber. Therefore, opt for high-fiber foods over high-starch ones. If you’re craving starch, choose better sources like whole grain bread over white bread or foods with more resistant starch, such as legumes.
Foods High in Fiber:
- Fruits like apples, bananas, oranges, raspberries, and strawberries
- Nuts and seeds—chia seeds, flax seeds, almonds, pistachios, sesame seeds
- Beans, especially navy and white beans
- Whole grains
Foods High in Starch:
- Corn
- Peas
- Rice
- Breads
- Potatoes
Why are complex carbs better for us?
Simple carbs break down faster, leaving you hungry sooner than complex carbs do. This can lead to more frequent consumption of simple carbs, which, if not used for energy, turn into fat. Simple carbs can also cause a spike in blood sugar and insulin levels, which we want to avoid as it can cause undesirable effects on body tissues over time.
Complex carbs, being digested more slowly, keep you fuller for longer periods and supply a steadier release of glucose into the bloodstream, causing a slower rise in blood sugar and a moderated insulin response.
What is the glycemic index?
Sometimes, we think all foods containing simple carbs are bad, and all foods with complex carbs are good. That’s not always the case. Simple carbs found in whole fruits, milk, and other healthy foods contain essential vitamins, minerals, and nutrients. We should avoid processed foods like sugary drinks and candy.
While complex carbs are generally better, we must also watch out for refined and processed complex carbs, like white bread and white rice, which have had many nutrients removed. This is where the glycemic index comes in handy. It rates how “healthy” a carb is based on its effect on blood glucose relative to pure glucose. Foods with a higher glycemic index cause a larger spike in blood glucose, while foods with a lower glycemic index cause a smaller or slower rise.
For better health, select foods with a lower glycemic index. These are often whole foods high in fiber, like apples, beans, lentils, and broccoli. High-glycemic index foods include cookies, cake, and French fries but can also include some surprising ones like sweetened dairy products, watermelon, and certain whole-wheat breads.
Easy Swaps for a Better Glycemic Response:
- Instead of white rice, eat brown rice
- Choose multigrain bread instead of white bread
- Opt for broccoli or leafy greens over corn
How do I get more of the right carbs in my diet?
To get the most out of your carbs, start your day with whole grains and use whole or multigrain breads for snacks and lunches. Check the ingredients list on your cereal or bread and make sure whole grain is listed first.
Another easy way to ensure you’re getting enough of the right carbs is to keep the skins on vegetables and fruits. The peels are generally very high in nutrients. For example, a whole apple contains up to 332% more vitamin K and 115% more vitamin C than a peeled apple, and they typically contain more fiber as well.
What kinds of foods should I avoid?
Avoid anything with lots of added sugars, including soda, baked treats, and fruit juices. Also, limit refined grains such as white bread, white rice, pasta, and crackers.
How many grams of carbohydrates should I eat per day?
According to the Dietary Guidelines for Americans, the average adult should aim to consume between 900 to 1300 calories (45–65% of calorie intake) from carbs per day.
As a general rule, fill around half to two-thirds of your meals with healthy carbs. Many of these should come from vegetables or higher-nutrient carbs like beans, brown rice, or quinoa.
Check the “total carbohydrates” section on nutrition labels of foods you eat regularly. Total carbs are broken down into sugars and fibers. Most people don’t get enough dietary fiber, so focus on foods with high fiber content and avoid those with added sugars.
For more insights and tips on carbohydrates and maintaining a healthy diet, stay tuned to our monthly Ask the Science Team posts, coming to you straight from Morecambe.